Method of repairing cracked metallic castings



April 2, 1940. Tv 2,195,741

. METHOD OF REPAIRING CRACKED METALLIC CASTINGS Filed June so, 1959 2] rwe/wbo'v 6* Lawrence .5. Scozf Patented Apr. 2, 1940 PATENT orF ca m-z'rnon or .nararnmo cnacrmn mn'ranuc cas'rnves Lawrence B. Scott, San Antonio, Tex.)

3 1 Claim. This invention relates to new and useful im-- provements in methods of repairing cracked metallic castings. Y One object of the invention is to provide an improved means, whereby broken or cracked metallic castings maybe readily and efllciently repaired so thatthestrength or durability of the repaired casting is substantially restored. An important object of the invention is to pro ,vide an improved method of repairing castings which includes, forming a groove or recess in the casting at substantially a right angle to the crack or break, said groove having an irregular outline, and then inserting metallic elements of substantially the same outline as the groove into said groove, whereby said element extends throughout the length of the groove and by its irregular outline is permanently ailixed in the casting and becomes a part thereof.

Another object of the invention is to provide an improved locking or fastening element or bar which has portions thereof reduced, whereby an elongate pin having an undulating or irregular outline is produced. a

A further object of the invention is to provide an improvedlocking element having its longitudinal sides formed with serrations or teeth which may be so disposed that when the. element is inserted in a groove or recess in the casting,

the teeth or serrations tend to exert a pulling together, or a spreading apart of the crack across which the groove and element extends.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing, in which an example of the invention is shown,

and wherein:

Figure 1 is a plan view of a looking or joining element, constructed in accordance with the in; vention,

Figure 2 is a transverse, sectional view, taken on the line 2-2 of'Figure 1, t

Figure 3 is a view, similar to Figure 1 of a, modified form of element,

Figure 4 is a transverse, sectional view, taken on the line 4-4 of Figure 3,

Figures 5 and 6 are views, similar to Figure 1 showing two other variations of the locking element,

Figure 7 is a plan view of a metallic casting, showing steps of the method of repairing said casting with the improved elements,

other.

Application June 30, 1938, Serial No. 216,665

Figure 8 is a partial transversefsectionai' view, taken on the line 8-8 of Figure 7, and Figure 9 is a schematic view, showing the method of forming the locking bar or element,

In the drawing, the numeral l0 designates a metallic bar or rod which is preferably cylindrical in cross-section although it may be ofany de-' sired shape. The 'lengthpf therod. may vary,- 1 as will be explained. The longitudinal sides of the bar or rod have an undulating or irregular m outline, whereby'the rod compresses a series of enlarged portions'A connected by reduced portions B. The enlarged portions are regularly spaced throughout the length ;of the rod and their edges are of a rounded contour, as is clearly 15 shown in Figure 1.

Any suitable method of forming the bar may be employed but it is preferable that the same be constructed as show 1i in Figure 9. An elongate rod, cylindrical in cross-section, is passed 30 between compression rollers l l and I! which rollers rotate in opposite directions to pull the rod therebetween. The rollers are similar in coni struction, each having its periphery formed with tion of the periphery of the roller locatedbetween adjacent lugs is curved inwardly to provide a curved recess i4 between each lug. When the elongaterod is passed between the compression rollers, the lugs I: of said rollers engage the outer 30 surface of the rod and indent or compress portions of said rod, asshown in Figure 7". The portions of the -rod passing between the curved recesses M are not compressed and thus, the alter nate enlarged portions A and connecting portions v 35 B are formed throughout the length of the rod.- The curvature of the recesses l4 curves the edges of the enlarged portions A and by changing the shape of the lugs l3 and recesses it, any desired contour may be given the rod. After the rod a has been passed through the rollers, it may be cut into proper lengths to form the locking bars Ill. In using the locking bars to repair a cracked or broken metallic casting C, a plurality of holes 45 15 are first drilled in the casting, as clearly shown is preferably at approximately right angles to the crack 0', which is being repaired. The holes may be of any desired depth and may vary in number, being drilled in close proximity to each After the holes are. so formed, the metal partitions it which are left between the holes are cut out by a suitable tool or chisel (not l tween openings.

shown). The entire partition is not removed but only the central portion of each, whereby inwardly extending projections I! are provided be- The distance between each pair of projections is substantially equal to the width of the reduced connecting portion B of bar ll. Thus, it will be seen that the completed groove is substantially of the same shape as the bar ll, being preferably slightly smaller than said bar, whereby when the bar is inserted therein, a tight or snug fit is had.

After the groove is completed, the bar I0 is inserted therein and driven downwardly by a suitable tool (not shown) so as to engage the bottom of the groove (Figure 8). The groove may be of any desired depth but it is preferable that the same be sufliciently deep to receive a plurality of the bars. After the first bar has been driven into the groove, a plurality of bars are then positioned within the groove on top of the same, and these'bars-completely fill the groove. Since the groove is slightly smaller than the bars, said bars are tightly wedged therein and the metal of the bars is forced into engagement with the metal of the casting. Due to the undulating or irregular longitudinal sides of the bar, as well as to the sides of the groove having a complementary outline, the bars M are locked within the casting and securely hold, the casting to prevent breaking thereof at the crack 0'. Each bar is solid throughout its length and since it is anchored at each end, it firmly holds the casting together. I

The undulated or irregular surfaces of the bar are subject to variation and it is not necessary that the enlarged portions A be rounded as shown in Figure l. The bar may be formed with the enlarged portions A pointed as shown in Figure 3 or the sides may be serrated or provided with teeth 20 as shown in Figures 5 and 6.

In inserting the bars having serrated edges, the holes l5 are first drilled and then the whole partition between the adjacent holes is removed, whereby a groove 2| having straight sides is formed. A suitable tool (not shown) is then driven into the groove 2| to provide vertical recesses 22 which are complementary to the teeth of the bars to be inserted. The serrated bars are then driven into the grooves so formed, as in the first form. t

It is pointed out that the teeth of the bar shown in Figure 5 are so disposed that when this bar is inserted in the groove, said teeth tend to spread the crack being repaired, while the teeth of the bar shown in Figure 6' tend to close the crack. The serrated bars, as well as the bar shown in Figure 3, may be readily formed by passing the same through compression rollers having peripheries of a proper contour to produce the serrations or teeth.

What I claim and desire to secure by letters Patent is: 1

The herein described method of repairing cracked or broken metallic bodies or the like, which resides in initially forming a groove in the body of predetermined depth and which intersects the crack and has the walls defining the sides thereof of undulating configuration, and finally driving into the groove a thick metal locking bar so as to cause flow of the metal of the bar, the latter being of solid cross-section and formed with a series of spaced knob-like projections which are substantially circular in crosssection and are connected by portions which latter in cross-section have convex side walls and substantially flat top and bottom walls, so as to provide alternating dales and hills, said bar being greater in width than the groove, the hills of the bar being substantially similar to the dales of the side walls defining the groove, and the dales of the bar being substantially similar to the hills of the said side walls of the groove whereby the sides of the bar have direct frictional contact with the adjacent side walls defining the groove, and the hills of the bar by and through the driving being flowed into the dales of the groove, so as to cause the bar after driving thereof to be of substantially rectangular crosssection throughout its length.

LAWRENCE B. sco'r'r. 

